It is known that a thiazole derivative represented by the following formula (I) or a pharmaceutically acceptable salt thereof has an adenosine A2A receptor antagonistic action, and is useful as a therapeutic drug for, for example, Parkinson's disease (see patent documents 1 and 2). In addition, a thiazole derivative useful as a therapeutic agent for sleep disorder, analgesic resistance to opioid, migraine, movement disorder, depression, anxiety disorder and the like is known (see patent documents 3, 4, 5, 6, 7 and 8). As these thiazole derivatives, compounds represented by the following formulas (IA), (IB), (IC), (ID) and the like, and the like are specifically known (see patent documents 1, 3, 4, 5, 6, 7 and 8).
(wherein R1 represents furyl, R2 represents pyridyl or tetrahydropyranyl, R3 represents aryl, aralkyl, an aromatic heterocyclic group, aromatic heterocyclylalkyl, aliphatic heterocyclylalkyl or tetrahydropyranyloxy, or these groups substituted by 1 to 3 substituents selected from the group consisting of halogen; lower alkyl optionally substituted by lower alkoxy or morpholino; lower alkoxy; lower alkanoyl; and vinyl)
As production methods of these thiazole derivatives, the following three production methods (Schemes 1-3) are known (see patent document 1).
(wherein R10 represents furyl or the like, Hal represents halogen, Ph represents phenyl, R12 represents as defined above for R2 or the like, and R11 represents as defined above for R3 or the like)
(wherein R10, R11 and R12 are each as defined above)

Other than the above, for example, a method including reacting α-halomethyl ketone and an N-(aminomethylene)thiourea derivative (see non-patent documents 1-4), a method including reacting α-halomethyl ketone and an N-acyl-thiourea derivative (see non-patent documents 3-6) and the like are also known.
More specifically, the compounds represented by the above-mentioned formulas (IA), (IB), (IC) and (ID) are described in patent document 1 as Examples 504, 508, 557 and 253.